3D-printed microfluidic device for high-throughput production of lipid nanoparticles incorporating SARS-CoV-2 spike protein mRNA

• Published in: Lab on a chip Vol. 24; no. 2; pp. 162 - 17
• Main Authors: Lin, Wan-Zhen Sophie, Bostic, William Kristian Vu, Malmstadt, Noah
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 17.01.2024
• Subjects: Connectors; COVID-19; Drug carriers; Encapsulation; Formulations; Humans; Lab-On-A-Chip Devices; Lipids; Liposomes; Lithography; Microfluidic devices; Microfluidics; Nanoparticles; Nanoparticles - chemistry; Nucleic acids; Polydispersity; Printing, Three-Dimensional; Proteins; RNA, Messenger - genetics; SARS-CoV-2 - genetics; Severe acute respiratory syndrome coronavirus 2; Sheaths; Spike Glycoprotein, Coronavirus - genetics; Three dimensional flow; Three dimensional printing; United States; Vaccines; Viral diseases; United States
• ISSN: 1473-0197; 1473-0189
• DOI: 10.1039/d3lc00520h

Lipid nanoparticles (LNPs) are drug carriers for protecting nucleic acids for cellular delivery. The first mRNA vaccines authorized by the United States Food and Drug Administration are the mRNA-1273 (Moderna) and BNT162b (BioNTech/Pfizer) vaccines against coronavirus disease 2019 (COVID-19). We designed a 3D printed Omnidirectional Sheath-flow Enabled Microfluidics (OSEM) device for producing mRNA-loaded LNPs that closely resemble the Moderna vaccine: we used the same lipid formulations to encapsulate mRNA encoding SARS-CoV-2 spike protein. The OSEM device is made of durable methacrylate-based materials that can support flow rates in the mL min −1 range and was fabricated by stereolithography (SLA), incorporating readily adaptable interfaces using commercial fluidic connectors. Two key features of the OSEM device are: 1) a 4-way hydrodynamic flow focusing region and 2) a staggered herringbone mixer (SHM). Superior to conventional planar fluid junctions, the 4-way sheath flow channel generates an evenly focused, circular center flow that facilitates the formation of LNPs with low polydispersity. Downstream, fluid mixing in the SHM is intensified by incorporating a zig-zag fluidic pathway to deliver high mRNA encapsulation efficiency. We characterized the mRNA-loaded LNPs produced in the OSEM device and showed that the enhanced 3D microfluidic structures enable a 5-fold higher throughput production rate (60 mL min −1 ) of LNPs compared to commercial multi-thousand-dollar micromixers. The device produced LNPs of diameter less than 90 nm, with low polydispersity (2-8%) and high mRNA encapsulation efficiency (>90%). The 3D-printed device provides a cost-effective and easily prepared solution for high-throughput LNP production. 3D printed OSEM device for mRNA-LNP synthesis.